1. Field of the Invention
The present invention relates to a thermostable acyl peptide hydrolase and a gene encoding the same. The enzyme of the present invention catalyzes a reaction to liberate an acyl amino acid alone from a protein or peptide having an acylated amino terminal, and thus is effective in amino terminal analysis.
2. Prior Art
Conventionally, mammal-derived acyl peptide hydrolases have been used for the analysis of acylated amino terminals of proteins and peptides.
Since such conventional enzymes are unstable at high temperatures, it has been necessary to perform the reaction described above at relatively low temperatures. However, performing the above reaction at a high temperature could bring a number of advantages, such as improvement of reaction efficiency, removal of microorganisms mixed in, etc. An enzyme which can be used at high temperatures and which is stable under high temperatures is strongly demanded. The present invention has been made under such technical circumstances, and it was an object of the invention to provide a thermostable acyl peptide hydrolase.
Toward the solution of the above problem, the inventor of the present invention paid attention to a superthermophilic bacterium thriving at 90-100.degree. C. and has found in its gene sequences a gene that is presumed to exhibit a thermostable acyl peptide hydrolase activity. Further, the inventor has produced an enzyme from the above gene using Escherichia coli and confirmed that the resultant enzyme is stable at high temperatures (90-95.degree. C.) and yet exhibits an acyl peptide hydrolase activity under such temperatures. Based on these findings, the present invention has been achieved.